When watering shade plants you should check the soil before you turn on the hose. Stick your finger 2 inches into the ground. If it feels dry at that depth then your plants need water. If it feels moist then wait another day or two before watering.
I learned to adjust my watering based on what my plants told me over several growing seasons. New shade plantings needed water twice a week during their first summer in the ground. My mature plants that have been in place for years only need water during dry spells that last more than a week.
Shade gardens hold moisture for shade perennials longer than sunny spots in your yard. Cool air under trees means less water evaporates from your soil surfaces. Less wind also slows drying in shaded areas. You often need to water less in shade than in full sun beds.
But tree roots compete hard for that moisture in your soil. University of Minnesota notes that tree roots spread through the upper 18-20 inches of soil. They can drain water fast during dry periods in summer. You may need to water more often near large trees than in open shade.
Shade garden irrigation needs thought about your specific site conditions. Drip systems work well because they put water right at plant roots where it helps most. Soaker hoses laid under mulch also do a good job for you. Avoid sprinklers that wet foliage since this can cause disease problems.
Water in the morning when possible for best results with your plants. This lets any wet leaves dry before evening falls. Wet foliage at night invites fungal problems that can damage your plants badly. Morning watering also means roots have moisture available during the heat of the day.
Check soil moisture at that 2-inch depth every few days during the first growing season. New plants have small root systems that dry out fast in hot weather. Once roots spread out over a year or two your plants will handle short dry spells much better on their own.
Mulch helps keep moisture in the soil between waterings in your shade garden. A layer of 2-3 inches of shredded bark or leaves slows evaporation from soil surfaces. It also keeps soil cooler on hot days which your plants will love. Your shade plants will need less water when you keep good mulch around them all season long.
Read the full article: 20 Best Shade Loving Perennials for Gardens
